The Food and Drug Administration (FDA) regulates the manufacture of tests for detection of HIV and HTLV infection. As part of the regulation of these products the FDA requires every lot to pass a lot release test consisting of a panel of sera having antibodies in differing concentrations to various viral antigens. This study uses the data from lot release tests to define the lot-to-lot consistency of manufactured kit in terms of reproducibility, sensitivity and specificity. A continuing data base of Lot release test results is being developed for each manufacture of HIV-1, HIV- 2, HIV-1/2 and HTLV-1 test kits. Data from lot release testing will be analyzed by descriptive statistics and regression analysis when sufficient data is accumulated.